Winter Cycling - Bike Lights in Winter

Hi everyone,

I'll be moving over to Kingston, Ontario, next month. Obviously I'll be building up a winter bike! My question is about lights, or more specifically about batteries, in winter...

I have a couple of sets of long-lasting NiMH and Li-Ion rechargeable batteries from my dark winter commutes (and marathon XC racing days) in the UK. I was thinking that these would do the job, but I have been told by some people that many such batteries will not work under certain temperatures.

So, will my rechargeables do? Or is rebuilding my front wheel with a hub dynamo the only solution? What are the working temperature ranges for different kinds of batteries?

Thanks!

I have the batterypack for my Silva LX (strapped to my helmet) in a Camelbak or in the backpocket of my winterjacket. No problem at minus 15 degrees celsius and would probably work great at much colder temperatures.

Hi everyone,

I'll be moving over to Kingston, Ontario, next month. Obviously I'll be building up a winter bike! My question is about lights, or more specifically about batteries, in winter...

I have a couple of sets of long-lasting NiMH and Li-Ion rechargeable batteries from my dark winter commutes (and marathon XC racing days) in the UK. I was thinking that these would do the job, but I have been told by some people that many such batteries will not work under certain temperatures.

So, will my rechargeables do? Or is rebuilding my front wheel with a hub dynamo the only solution? What are the working temperature ranges for different kinds of batteries?

Thanks!

I've found that they'll work just fine in the cold (-32c is the coldest I've tried with NiMH and -25 with Li-Ion), although you'll get shorter runtimes with the NiMH and maybe with the Li-Ion too, but I've never runout of Li-Ion juice so I'm not sure.

my findings with HID lights....NiMH rules the cold

lithium with led....runtimes are noticably shortened by cold

I run a NR trinewt with the Li-Ion pack, and found that leaving the battery in the garage on the bike is a bad thing- no juice available.

I take the battery pack in the house now so it stays warm.

I have an hour commute, and the battery does just fine down to -15F or -25C. I do have the battery pack in a water bottle- both so it fits in a cage, and to protect it somewhat.

Shorter run times, but otherwise no issues.

I commuted in Kingston for three years in the mid-90's. For the most part, the snow is well dealt with by the ploughs, but there will be days where you're into 6" of powder. The days when we had freezing rain made commuting impossible, but they are rare. I don't think you'll have any problems with your lights as the temperatures are usually not too extreme, but I do recommend full-blown goggles when there is any snow as the wind off the lake can make it pretty hairy.

I don't know about NiMH, but with both alkaline and lithium batteries the colder it is the shorter the battery life.

Ok, i don't know who recommended NiMH batteries but that was stupid.

" The Li-Ion battery loses only about 12% of its capacity at -20 degrees Celsius, compared to about 80% for the NiMH battery. "
More here:

http://nordicgroup.us/battery/#Advantages_of_Li-Ion_Batteries/Disadvantages_of_NiMH_batteries_(AA/AAA)_

Further, the voltage curve of a lithium ion means the light stays night and bright right until the charge is lost, with the NiMH battery the light dims and successively dims, making it increasingly dangerous to be cycling at night!!

Trust me, i'd moved everything over to lithium ion even if they are more expensive.

My system runs on NiMH batteries that are charged by the hub, in operation year round, never taken taken out for home warming or anything. I do not really have any winter lighting problems while riding in any temperatures that occasionally get down to -25C, likely not much different from Kingston. I just checked the data for the batteries which have been continuously in that system for 5 years or so and they have now 60% of the nominal starting capacity.

Lightman strobes with freshly charged brand new NiMH's will last about 20 minutes or less when it's 10 to 20 below 0F, generic led blinkies with cr2032's last a little bit longer. They both come back to life after 30 minutes at room temperature.

Thanks people, all very useful...

It sounds like you have some lights and batteries, so just give try it and see. My experience is Li-ion is a better battery, all around. My personal preference is for generator hub and really bright lights, IQ Fly or better. I ride with a light on during the day also, at times, for visibility. I try not to drive a car so I spend lots of time out and about, I found remembering to charge the battery to great a task for my brain :-)

ps: High visibility , conspicuity tape, is super.
http://www.identi-tape.com/conspicuity.htm

I wish I could comment on your main issue, but my handlebar light on my winter bike is a dynamo light (a Lumotec Cyo). I just wanted to mention not to forget that if you use a helmet light like I do, and keep the batteries in a jersey back pocket inside your jacket like I do, they're protected so cold isn't an issue.